There is a strong and rapid push towards the implementation of health information systems in a variety of health care contexts, including emergency departments (EDs). Health care information systems are advocated as solutions to a variety of problems including cost, efficiency, patient safety, and medical errors. However, the critical challenge is in creating information technology solutions that actually deliver the benefits that are promised. New technologies are often designed with only a limited understanding of the work they need to support and the people who will use the systems, or are designed with a focus on administrative functions rather than patient care functions. Researchers in numerous other complex, safety critical domains have documented hazards and difficulties that can be traced to the design of new information technology. Without a careful understanding of how new technologies will be used in practice, or the barriers to their use as expected, new technology can lead to unanticipated, undesirable consequences. These may include increased workload due to new processes or work-arounds, or serious safety compromises if systems are bypassed or abandoned, or critical tasks interrupted. One form of technology that is being developed to improve efficiency and safety in ED settings is computerized patient tracking. These systems are intended to replace manual status boards that are commonly used for managing ED work. Status boards (typically, large whiteboards) contain medical and logistical information about patients and provide clinical and support staff with information about patients as well as higher level information regarding hospital state and team coordination information. Currently implemented electronic versions of the status boards may mimic the look and layout of manual boards, allow information on the status board to be accessed at different locations in the hospital and provide automated recording keeping and reporting. However, research shows that they also impose new constraints on use, miss the opportunity to best support the work of the healthcare providers, and introduce new sources of error and unanticipated consequences. This research proposes to utilize simulation and cognitive systems engineering methods to design and test prototype ED information systems which are based on an in depth understanding of the task and activities of caregivers and staff within the ED. A multi-phase strategy will be used in which key aspects of ED activities will be modeled, prototypes will be iteratively developed, and prototypes will be assessed in an clinical simulation center environment. The research outcomes will impact EDs as they implement electronic ED information systems, insuring that these systems actually do improve efficiency and safety, decrease ED wait times, and decrease unnecessary iatrogenic injuries to patients throughout the US.